Ball joints of this sort are known from the current state of technology. The DE-PS 35 02 233 describes an example of a ball joint in which the inner space of the housing serves as receptacle for a ball, that is comprised of two bearing shells, made of a hard elastic plastic, that are inserted between the joint housing and the ball and two thrust collars, made of a soft elastic plastic, that adjoin the outer surface of the bearing shells with their inner surface. The bearing shells have surfaces conically tapered towards the outer portion of the joint, in the contact area of the thrust collars, whereby the thrust collars, with their concave curved outer surface brace themselves on these conically tapered surfaces. In all these previously mentioned ball joints the thrust collars, which preferably consist of polyurethane, are deformed during the mounting process by pressure in the axial direction until the required bracing of the joint is obtained. The formed elastic collars thus serve for the production of the necessary tension in the joint, as well as for the equalization of the tolerances occurring in the ball joint. The previously mentioned ball joints have proven themselves in practical application. However, such polyurethane collars can lead to an undesired change of the axial pressure after they have been mounted. These changes are primarily caused by a material flow in the existing hollow spaces. This also leads to a reduction in the frictional values and the bracing of the joints, but the elasticity of the joint is increased.
Another ball joint is known from the DE-PS 28 31 470, in which end pieces in the shape of spherical zones are connected with a rubber body in a bonding manner and the rubber body is connected in a bonding manner with a spherical inner portion that is provided with two cylindrical mounting ends on the inner side and with a cylindrical center section of a housing on the outer side. The end pieces are secured against rotation opposite the housing and act like thrust collars with webs that adjoin the bearing shell and extend transversely to the axial direction of the housing, as well as with two limbs bent off the same. The forces that brace the joint in the axial direction are introduced into one of the two limbs.
One disadvantage of this previously mentioned ball joint is the fact that the end pieces that act as thrust collars are not formed elastic, so that the bracing of the joint is influenced by the inherent elasticity of the end pieces. Possible wear and tear of the ball joint is thus not equalized by the end pieces or the spherical inner portion.
The DE-OS 20 62 475 describes one further ball joint comprised of an inner ring with a spherical outer surface and an outer ring with a correspondingly spherical inner surface that serves as receptacle for the inner ring.